In vertebrates, cervical vertebrae (singular: vertebra ) is the neck vertebrae, just below the skull.
The thoracic vertebrae in all mammalian species is the vertebra which also carries a pair of ribs, and lies down to the cervical spine. Further the caudal follows the lumbar vertebra, which also belongs to the stem, but does not carry the ribs. In reptiles, all the spinal ribs carry the ribs and are called dorsal vertebrae.
In many species, although not in mammals, the cervical spine bears the ribs. In many other groups, such as lizards and saurischian dinosaurs, large neck ribs; in birds, they are small and completely blend with the vertebrae. The transverse process of the vertebral mammals is homologous to the other cervical amniote ribs. Most mammals have 7 cervical vertebrae.
In humans, the cervical vertebra is the smallest of the true vertebrae, and can be easily distinguished from the thoracic or lumbar region in the presence of the foramen (hole) in each transverse process, through which the vertebral artery, the vertebral and inferior vein of the cervical ganglion pass.
The rest of this article focuses on human anatomy.
Video Cervical vertebrae
Structure
By convention, the cervical vertebra is numbered, with the first (C1) closest to the higher-grade skull and vertebra (C2-C7) moving away from the skull and into the spine. The general characteristics of the third to sixth cervical vertebra are described here. The first, second, and seventh vertebrates are amazing, and detailed later.
- The fourth body of this vertebra is small, and wider from side to side than from front to back.
- The anterior surface and posterior is flat and has the same depth; the first being placed at a lower level than the last, and the inferior limit is extended downwards, resulting in the overlap of and the front of the vertebra below.
- The top surface is concave across, and presents the projection lip on both sides.
- The lower surface is concave from front to back, convex from side to side, and presents a lateral shallow concave that receives the corresponding projection lip of the underlying vertebra.
- The pedicle is directed laterally and backward, and attaches to the body between its upper and lower limits, so that the superior vertebral notes are inferiorly deep, but at the same time, narrower.
- The teacher is narrow, and thinner on top than below; large vertebral foramen, and triangle shape.
- Short and bifid spinous processes, two divisions are often not the same size. Because the spinous process is so short, certain superficial muscles (trapezius and splenius capitis) attach to the nuchal ligament rather than directly to the vertebrae; the nucal ligaments themselves are attached to the C2-C7 spinous process and to the posterior atlas tubercle.
- The articular process of the superior and inferior cervical vertebrae has fused on one or both sides to form the articular pillar , the laterally projecting bone column of the pedicle and lamina junction.
- Flat articular facets and oval shapes:
- face superior facing backward, upward, and slightly to medial.
- the face inferior is facing forward, down, and slightly to the side.
- The transverse processes are each punctured by the transverse foramen, which, in the upper six vertebrae, gives part to the vertebral arteries and veins, as well as the sympathetic nerves plexus. Each process consists of the anterior and posterior parts. These two parts combine, outside of the foramen, by a bar of bone that shows a deep sulcus on its upper surface to pass through the corresponding spinal cord.
- The anterior portion is the rib homologue in the thoracic region, and is therefore named the costal process or the cost element . It arises from the side of the body, directed laterally in front of the foramen, and ends in the tubercle, anterior tubercle.
- The posterior part, a true transverse process, arises from the vertebral arch behind the foramen, and is directed forward and laterally; it ends up in a flat vertical tuberkulum, posterior tuberkulum.
The anterior tubercle of the sixth cervical vertebra is known as carotid tubercle or Chassaignac tubercle . This separates the carotid artery from the vertebral artery and the carotid artery can be massaged against this tubercle to relieve symptoms of supraventricular tachycardia. Carotid tubercle is also used as a landmark for brachial plexus anesthesia and cervical plexus.
The cervical spinal nerves arise from above the cervical vertebrae. For example, the cervical spinal cord 3 (C3) passes above C3.
Atlas and axis
Atlas (C1) and axis (C2) are the two uppermost vertebrae.
Atlas, C1, is the uppermost vertebra, and along with the axis; forming a connection that connects the skull and spine. Its main specificity is that it has no body because the atlas body has merged with its axis.
The axis, C2, forms the axis at which the atlas rotates. The most distinctive feature of this bone is the powerful odontoid (nest) process that radiates perpendicularly from the upper surface of the body. The body is deeper in front than at the back, and extends forward anteriorly so that the upper and front overlap of the third vertebra.
Vertebra prominens
The prominens vertebrae , or C7, has a distinct and distinct spinous spinous process, which is palpable from the skin surface. Occasionally, the seventh cervical vertebrae are associated with an abnormal rib, known as the cervical rib, which develops from the anterior root of the transverse process. These ribs are usually small, but can sometimes suppress blood vessels (such as subclavian arteries or subclavian veins) or nerves in the brachial plexus, causing pain, numbness, tingling, and weakness in the upper limb, a condition known as chest outlet syndrome. Very rarely, this rib appears in a pair.
The long spinous process of C7 is thick and almost horizontal in direction. It is not branched, and ends up in tubercles that are attached to the nuchae ligament. This process is not always the most prominent of the spinous process, which is found to be only about 70% of the time, C6 or T1 can sometimes be the most prominent.
The transverse process has a size large enough, the posterior root is large and protruding, while the anterior is small and marked faintly; each top surface usually has a shallow sulcus for the eighth spinal nerve, and its extremities rarely present more than one bifurcation trace.
The transverse foramen may be as large as that of other cervical vertebrae, but generally smaller on one or both sides; sometimes it's double, sometimes it's not there.
On the left side occasionally gives part to the vertebral artery; more often the vertebral vein crosses both sides; but the usual arrangement is for both arteries and veins passing in front of the transversus process, and not through the foramen.
Maps Cervical vertebrae
Function
The movement of head nods primarily occurs through flexion and extension of the atlanto-occipital joint between the atlas and the occipital bone. However, the cervical spine is relatively immobile, and some components of this movement are due to flexion and extension of the vertebral column itself. This movement between the atlas and the occipital bone is often referred to as "yes together", because it is capable of moving the head in a way up and down.
Movements shake or rotate left and right heads occur almost entirely on the connection between the atlas and the axis, the atlanto-axial joint. A small amount of rotation from the vertebral column itself contributes to movement. The movement between the atlas and the axis is often referred to as "no connection", because it is capable of turning the head side by side.
Clinical interests
Cervical degenerative changes arise from conditions such as spondylosis, intervertebral disc stenosis, and osteophyte formation. This change is seen in the radiographs used in the scoring system from 0-4 ranging from no change (0), to early with minimal development of osteophytes (1), mild with defined osteophytes (2), moderate with additional disc or discontinuous stenosis (3), to the stage of many large osteophytes, severe constriction of the disc space, and more severe vertebral end plate sclerosis (4).
Injury to the cervical spine is common at the level of the second cervical spine, but neurologic injury is rare. C4 and C5 are areas that see the highest number of cervical spine trauma.
If that happens, it can cause death or severe disability, including arm, leg, and diaphragm palsy, leading to respiratory failure.
Common patterns of injuries include odontoid fractures and hangman fractures, both of which are often treated with immobilization in the cervix or brace Halo.
A common practice is to paralyze the patient's neck of the spine to prevent further damage during transport to the hospital. This practice has been reviewed recently because the incidence rate of unstable spinal trauma can be as low as 2% in immobilized patients. In cleaning the cervical spine, Canadian studies have developed the Canadian C-Spine Rule (CCR) for doctors to decide who should receive radiological imaging.
Landmarks
The vertebral column is often used as a marker of human anatomy. These include:
- In C1, the base of the nose and the hard palate
- In C2, the gear is closed
- In C3, jawbone and mandible
- In C4, a common carotid artery bifurcation.
- From C4-5, thyroid cartilage
- From C6-7, cricoid cartilage
- In C6, the esophagus continues with the laryngopharynx and also the larynx becomes continuous with the trachea. This is also the level at which the carotid pulse can be palpated against the transverse process of the C6 vertebra.
Additional images
See also
- Vertebral column
- Cervical fracture
References
This article combines text in the public domain of page 97 of the 20th edition of Gray's Anatomy (1918)
External links
- The diagram at kenyon.edu
- Cervical Spine Anatomy
- Mnemonic for Landmarks
- Cervical vertebra quiz
Source of the article : Wikipedia
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